FREDERICKSBURG, Va. - Blowing up a dam isn't easy - just ask the Army Corps of Engineers.
The Corps, better known for building dams than tearing them down, misfired in its first attempt to blow up the Embrey Dam across the Rappahannock River here yesterday, producing a "poof" instead of a "kaboom" when it set off only a fraction of the 650 pounds of explosives planted in the dam.
An hour later, the second try for Operation Noah Shiva, as it was known, produced a large blast of smoke, water and debris, clearing a 100-foot hole in the dam to let water and fish pass through.
The successful explosion raised a cheer from the crowd of several thousand, many of whom waited for hours near a reviewing stand set up by the city outside a 1,000-foot safety zone.
"That was definitely more like it," said a relieved and beaming Brian Rheinhart, the Corps of Engineers project manager.
The demolition is part of an effort to restore the natural flow of rivers by removing dams - nationally and in the Chesapeake Bay watershed. Conservation groups have been working since the 1980s to bring down dams and put up fish ladders or lifts over remaining ones.
Nationally, an estimated 600 dams have been removed in recent years. Many, built as hydroelectric power sources, have become outdated and face regulatory reviews that could require fish passages, according to American Rivers, an environmental group.
The Embrey dam, built in 1910, stopped generating power in the 1960s.
Maryland officials have no plans to blow up any dams in the state, but they do hope to remove several in the next few years.
"Removals are the best option going," said Jim Thompson, fish-passage coordinator for the state Department of Natural Resources, who came to see the explosion yesterday.
DNR plans to use construction equipment this summer to remove the Octoraro Dam, on Octoraro Creek near Rising Sun.
But at 22 feet high and 770 feet long, the Embrey dam was the largest in the bay watershed slated for removal - and the only one expected to require explosives.
For some, the demolition represented the end of a personal link to the past, when communities depended on hydroelectric power.
"I think in the end, my grandfather would have supported all this," said A. Thomas Embrey III, a local banker who spoke at the event. The dam was named after his grandfather, Alvin T. Embrey, a prominent judge.
The dam's demolition opened up 700 miles of the river and its tributaries to migratory fish - including American shad, hickory shad and blueback herring - for the first time since 1854, when a wooden dam was built, said John Tippett, executive director of the Friends of the Rappahannock.
Tippett is credited with persuading Virginia Sen. John W. Warner to support the demolition of the dam.
Fishermen and boaters will see the results of the project almost immediately, Tippett said. Shad are expected to return this spring, and the 22-foot drop that inspired the dam construction will create good conditions for whitewater rafting.
"This is the culmination of 20 years of work," Tippett said.
Corps officials said the project wouldn't be completed until 2006, when a contractor finishes removing the rest of the dam and retrieves all of the concrete debris from the river.